1. Field of the Invention
The present invention relates to a data processing system and a data processing method and, more particularly, to an improvement in an apparatus and method of saving data from a main memory into an auxiliary memory.
2. Description of the Related Art
When a fault occurs in a computer system, and the system is unavoidably stopped, the contents of a main memory at the time of the stoppage of the system are useful for analysis of the fault. For this reason, in a conventional system, the contents of a main memory at the time of the stoppage of the system are saved in an auxiliary memory.
In conventional systems, the contents of a main memory can be saved in an auxiliary memory within a relatively short period of time. For example, if the storage capacity of a main memory is 5 Mbytes, and a data transfer speed is 5 Mbyte/sec, the contents of the main memory can be saved in an auxiliary memory within almost one second.
With the progress of the semiconductor technology, the storage capacity of a main memory has been greatly increased. However, there is not much increase in speed of data transfer between a main memory and an auxiliary memory with the present data save techniques, therefore, it may require a long period of time to save the contents of a main memory in an auxiliary memory in the future. Assume that a computer system has a G (giga)-byte-level main memory, and the speed of data transfer to an auxiliary memory is not much increased. In this case, it takes a very long period of time, i.e., several tens minutes to one hour, to save the contents of the main memory. It is not preferable to take such a long period of time to save data. Furthermore, in general, a computer system is rarely allowed to stop for a long period of time. The computer system is normally required to be restarted immediately after the stoppage. However, the system cannot be immediately restarted if it takes a long period of time to save data.